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Boeing AGM-69 "SRAM"
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The SRAM (Short Range Attack Missile) was a relatively
small standoff missile for use by USAF's B-52 and FB-111A strategic
bombers. On the B-52, it replaced the AGM-28
Hound Dog.
Each SAC B-52 G and H model bomber
could carry up to 20 SRAMs, six on each of two wing pylons and eight
on a rotary launcher located in the bomb bay. The FB-111, on the other
hand, could be equipped with a total of six missiles, two mounted
internally and four carried on wing pylons. The B-1B was designed to
carry up to 24 SRAMs on three rotary launchers, each equipped with
eight SRAMs. Originally, the SRAM's primary mission was to improve the
survivability of the SAC manned bomber force through the
"neutralization of surface-to-air missile defenses." The mission was
later expanded to encompass a secondary objective, the destruction of
selected strategic targets.
The first B-52 and FB-111 units to become
operational with the new missile were the 42nd Bomb Wing (B-52G),
Loring AFB, Maine, on 15 September 1972, and the 509th Bomb Wing
(FB-111), Pease AFB, New Hampshire, on 1 January 1973. On 20 August
1975, the last 1500 SRAMs were delivered to SAC's 320th
Bombardment Wing, Mather AFB, California. The first live launch of a
SRAM from a SAC operational B-1B took place on 3 June 1987.
After the cancellation of the
GAM-87/AGM-48 Skybolt ALBM (Air-Launched Ballistic Missile)
in December 1962, the USAF had to find another way to modernize the
strike capabilities of its strategic bomber force. In March 1964, SOR
(Specific Operational Requirement) 212 for a short-range attack
missile was submitted by the USAF, and in March 1965, development was
approved by the Department of Defense. The design competition was won
by Boeing, who received a development contract in October 1966. The first powered flight of an AGM-69A occurred in
July 1969, and in January 1971, full scale production of the SRAM
was approved. In August 1972, the SRAM was operational with SAC
units, and quickly replaced the AGM-28
Hound Dog as the B-52's standoff attack missile.
The AGM-69A was a ballistic-type air-to-ground missile powered by a
Lockheed SR75-LP-1 two-stage solid-fuel rocket motor, and armed with a
200 kT W-69 thermonuclear warhead. The first motor stage propelled the
missile to Mach 3 after launch, and the second stage was ignited near
the target for a powered terminal approach. Maximum range varied from
55 km (35 miles) for low-altitude launches to 160 km (100 miles) for
high-altitude firings. The SRAM was guided by an General
Precision/Kearfott KT-76 inertial navigation system, assisted by a
Stewart-Warner terrain clearance sensor, and could achieve an accuracy
of about 430 m (1400 ft) CEP. The B-52 Stratofortress could
carry 8 SRAMs on a rotary launcher in the bomb bay, and up to
12 more on two external 6-missile pylons. The FB-111A could carry up
to 6 SRAMs. When carried externally, an expendable tail faring
was used on the missile to reduce drag. The AGM-69A greatly increased
the number of targets which could be attacked by a single bomber, and
made it possible to attack known (fixed) air-defense installations en
route to the primary target.
Several proposals were made to improve the versatility of the
AGM-69A, including a radar guidance system to use it as an air-to-air
missile, or an anti-radiation seeker to attack mobile air-defense
radars, but none of these features were adopted. In the mid-1970s,
however, storability problems with the rocket motor surfaced, and in
1976 Thiokol was awarded a contract to develop a new motor for SRAM.
In 1977, the new motor was combined with other upgrades, including an
improved guidance system (with enhanced computing capability) and the
W-80 warhead of the AGM-86
ALCM. The new SRAM missile, designated AGM-69B
SRAM B, was intended for use by the B-1A. In 1978, however, the
B-1A was cancelled, and the USAF found a way to extend the lifespan of
the old motor to the originally planned 5 years, and these two events
killed the AGM-69B program. Instead, it was then planned to eventually
replace the AGM-69A with the AGM-86
ALCM and the forthcoming
ASALM (Advanced Strategic Air-Launched Missile). The latter,
however, was also cancelled in 1980. When the B-1 program was
resurrected (as B-1B) in 1981, it was decided to develop an entirely
new weapon, later to be known as AGM-131
SRAM II.
In June 1990, the AGM-69A SRAM was retired from the USAF
inventory. Various reasons have been quoted, including unreliability
of the warhead and the rocket motor. The AGM-131
SRAM II was cancelled the following year, leaving
effectively a gap in the capability of the USAF's B-52 bomber force. A
total of about 1500 AGM-69A missiles were built by Boeing until
production ended in 1975. |
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| Specifications |
| Length |
4.27 m (14 ft) (4.83 m (15 ft 10 in) with tail fairing) |
| Fin Halfspan |
38 cm (15 in) (fin tip to centerline) |
| Diameter |
45 cm (17.5 in) |
| Weight |
1010 kg (2230 lb) |
| Speed |
Mach 3 |
| Range |
160 km (100 miles) |
| Propulsion |
Lockheed Propulsion Co. SR75-LP-1 two-stage solid-fueled
rocket |
| Warhead |
W-69 thermonuclear (200 kT) |
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